The present invention relates to a seat supporting apparatus suitable for an automobile seat capable of being freely folded up or erected (or molded down) as well as being attachable and detachable with respect to an automobile floor panel.
According to a vehicle such as a van type one, when the number of passengers is large, an auxiliary seat is fixed onto a floor panel of the vehicle and when the number of loaded articles is large, the auxiliary seat is removed to thereby keep the large loading space. As proposed by, for example, Japanese Patent Laid-Open Publication No. 86230/1997 or Japanese Utility Model Laid-Open Publication No. 58453/1993, an attachable and detachable seat of this kind has a basic structure in which a seat supporting member is made attachable to and detachable from a pair of strikers fixed to a floor of a vehicle. Whereas a rear striker is simply attached to and detached from a front hook portion of the seat supporting member, a rear striker is attached to and detached from a ratchet mounted to the seat supporting member and movement of the ratchet is controlled by a pawl.
According to the seat supporting apparatus of the above-described conventional examples, whereas when a seat is forwardly tilled or collapsed, the front striker is brought into contact with a U-like groove of the hook portion fixed to a base member and the seat is folded forwardly centering on the point of contact, in erecting the seat, the rear seat is tied to the front seat by using a string or the like to thereby maintain the folded state of the seat. Or, another means for keeping the seat from returning to the original position, newly changing the seat position, moving the gravitational center of the seat forward.
Such a means is not favorable for elevating (or collapsing) the seat in a safe state because it cannot firmly prevent the seat from rocking or returning to the original position unexpectedly.